Double capacity of a codon

2009/02/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Biokimika
• Genetika

In the protozoo Euplotes crassus, researchers at the University of Nebraska of the United States have found that the UGA codon can encode two amino acids. Normally, a elbow encodes a single amino acid. The UGA codon can encode cysteine and selenocysteine amino acids.

The key is in a genetic sequence located at the end of the messenger RNA chain, in the SECIS sequence. This sequence generates a loop in the RNA string and when reading the ribosome read the modified message of the UGA codon. Without this they have seen that the codon encodes the amino acid cysteine and with it the amino acid selenocysteine.

In the future, the objective of the research team is to analyze how the SECIS sequence specifically modifies the UGA code and see if this variability of this elbow can occur in the rest of organisms.